Abrasive compound



' facture and also produces a better finish. In

Patented Oct- 15, 1929 UNITED. STATES PATENT OFFICE JOSEPH N. BOURG AND WESLEY A. RICHARDS, OF DETROIT, MICHIGAN, ASSIGNORS TO PARK CHEMICAL COMPANY, OF DETROIT, MICHIGAN, A CORPORATION MICHI- GAN ' ABRASIVE COMPOUND I No Drawing.

The invention relates to, a compound adapted to be used for rubbing down wood or metal surfaces after the application of one or more coats of lacquer, paint, varnish 5 or nitro-cellulose finishes in order to prepare the surface for further finish coats.

One of the objects of the invention is to produce a compound adapted for the removal of rough and uneven surfaces or ini- I 10 perfections of a like nature with ease and speed and without causing other imperfections or discolorations.

Another object is to provide a compound, which when used for rubbing down the undercoatings-or final color coats .produces a surface having a higher polish or gloss.

Another object is to provide a compound which after using may be removed from beaded, scrolled or angular surfaces easier and more completely than is the case in the present state of the art.

Our new compound is particularly adaptable for use in rubbing down automobile bodies since it reduces the amount of time required, thereby lessening the cost of manuthe present state of the art it is common'practice to remove the rough surfaces which are produced after the application of theundercoatings of primer and lacquer by rubbing with sand paper, wet or dry, or by using sand and oil, pumice and water, or similar abrasives. This method, however, results in an uneven cutting or removing of roughness, 18 slow and difiicult in operation and produces scratches and streaks due to unevenness of the abrasive materials and uneven application of pressure. This is due primarily to the fact that theabrasive does not have freedom of motion, this beingparticularly true in the case of sand paper where the abrasiveparticles are permanently fastened to a paper backing. The difficulty is still further accentuated by the use of blocks to back up the sand paper. Where mixtures of abrasive and oil or water are used, the drying out and piling up of abrasive also brings about the same undesirable results.

Mixtures are also used containing various solvents such as amyl acetate which assist the I Application filed April 27, 1925. Serial No. 26,288.

action of the abrasive and result in a softening and permanent injury to the finish.-

. has entire freedom of movability. This per-' 'mits all particles of abrasive to level off and seek the same relative plane, thereby result ing in a much more uniform cutting action and a smoother surface free from deep scratches. The new compound can be made in various consistencies ranging from a stiff paste to a thin liquid, but we have found that the thinner compoands are preferable as long as the abrasive stays in suspension since it permits of easier application to the surface. It is also important that the compound be homogeneous and that the various ingredients incorporated in the mixture be so mixed that no separation of the constituents takes place under ordinary working conditions and tem erature's.

The following is an example of a specific compound embodying our invention and the process of compounding the same: 2 parts soap are introduced into 28 parts of water and the whole brought to a temperature 175 F., this temperature is maintained until the entire amount of soap is dissolved. 28 parts of kerosene are then added during rapid mechanical agitation. This agitation is continued and 42 parts by weight of pumice, tripoli, or other suitable abrasives are then gradually introduced. The agitation is continued until the whole mixture begins to thicken enough so that the abrasive will not settle out. This occurs at about room temperature.

Another example of the preparation of a compound embodying our invention is as follows :One pound each of good quality stearic acid and oleic acid dissolved with the aid of heat in'twenty-three pounds of mineral oil. We use an oil of low viscosity but of flashpoint suflic'iently high to render the same safe to use; I This 011 must be a refined and distilled oil containin a minimum amount of foreign -matter., this mixture at a temperature of 175 F., are added twentyfive pounds of water at the same temperature containing-four ounces caustic potash the oil exists as tin globules surrounded by water. Water is t e external phase and as such enables the compound to easily assimilate and add itself to water thus rendering removal after using, easy. If oil were the external phase the compound would not wet with water and removal with water would be very difficult. Also, a compound where oil is the external phase will not adhere to vertical surfaces or pads as readily as if water is the external phase. In other words, we have foundthat in the manufacture of this compound in'substantially the manner and proportions indicated, the oil is the internal phase in relationship to the water. The oreating of this condition is one of the fundamental objects of our invention.

We-do not wish to limit ourselves to the exact composition or percentages given above nasmuch as our invention contemplates other mixtures which can be used to support or carry the abrasive mentioned or similar abrasives. As a further example, of a compound which can be used for. the same purpose, the abrasive may be supported in an emulsion of oil and water with a suflicient addition of wax to stiffen the same and main tain it permanent in character. Other alternative compounds may be formed by supporting the abrasive in amixture consisting of a saponifiable oil with, or without the addition of wax, or the gums or waxes may be-used alone to support the abrasive in susension. Furthermore, a mixture thickened y use of a plastic clay or similar material will also act as a suspending medium.

In all of the compounds as above described,

' the abrasive material is incorporated in a soft mass to form a homogeneous mixture of such a nature that the suspended abrasive particles have freedom-of movability and therefore, will not cause as deep scratches in the surface as would result from the use of a similar abrasive when permanently secured to a backing materigl. Thus, with our new compounds it is possible to use sharper and coarser abrasive materials without producing dee scratches or imperfections which will inter ere with the subsequent coats of lacquer or other finishing material.

Since the amount ofmaterial to be removed, the condition of the surface and the resulting surface desired differ in many cases, we do not limit ourselves to the use of any particular abrasive, but make up the compound with abrasives adapted to the removal of greater or lesser amounts of material and con-- sequently faster or slower cutting action depending on the particular work to be done.

The following are examples of abrasives .that might be incorporated either singly or in combination in the new compound according to our invention: pumice, tripoli, rottenstone, silica, kiesel-guhr, infusorialearth,iron oxide, alundum and chalk.

A more specific example of an abrasive giving very fastcutting properties to the compound Without producing objectionable scratching is pumice which has been bolted through a 110 mesh Tyler standard screen and is of such fineness that 97 per cent will pass through a 200 mesh screen.

It is also to be understood that a small quantity of perfume may be added to the emulsion during preparation to give the compound a more agreeable odor.

What we claim as our invention is 1. A compound adapted for use in the smoothing or cutting down of painted, varnished, or lacquered surfaces consisting of an emulsion of kerosene and water approximately 56%, tripoli approximately 42% and stearate soap approximately 2%, said stearate soap being present in high enough concentrations in the water phase to form a jelly and thus hold the kerosene and abrasive in permanent suspension.

. 2. A compound adapted for use in the smoothingor cutting down of painted, var- I nished, orilacquered surfaces consisting of kerosene 28%, water28%, abrasive 42% and soap 2%, said soap 'being present in high enough concentrations in the water phase to form a jelly and thushold the kerosene and abrasive in permanent suspension.

3. A compound adapted for use in the smoothing or cutting down of painted, varnished, or lacquered surfaces consisting of an emulsion of alight mineral oil and water approximately 56%, abrasive approximately 42% and soap approximately 2%, said soap being present in high enough concentrations in the water phase to form a jelly and thus hold the oil and abrasive in permanent suspension.

In testimony whereof we tures.

JOSEPH N. Boone. WESLEY A. RICHARDS.

afiix our signa- 

